In the performance of surgery in the chest cavity, generally referred to as thoracic surgery, it is desirable to hold open the surgical cavity to provide access to the organ or body part upon which the surgery is being performed. This is especially important in the case of cardiac surgeries. An early example of a surgical retractor for use in coronary bypass surgical procedures which include dissection of the internal mammary artery is disclosed in U.S. Pat. No. 4,622,955, which is incorporated by reference.
In the device of U.S. Pat. No. 4,622,955 plural rakes which engage the body and retract the surgical cavity formed by a midsternotomy are relatively fixedly positioned with respect to each other from a rod. The rod may be elevated or lowered, as desired. However, there is no adjustment for the rakes relative to the rod, to each other or to the surgical cavity. Furthermore, the rakes are generally small, having sharply pointed tips and are generally designed to be employed in pairs for the purpose of retracting one side of a sternum which has been split by a midsternotomy. The device of U.S. Pat. No. 4,622,955 cannot provide the support required for other procedures which have been recently developed as alternatives to the midsternotomy approach to the coronary bypass, and it is not adapted for use in reoperative midsternotomy procedures.
It is well known and appreciated that in surgical procedures, time is of the essence, and delays associated with adjustments of support equipment are unwanted. Additionally, during certain procedures, it may be desirable to impose or to change a biasing force on a body portion which is undergoing a surgical procedure or treatment. Further, it is desirable to minimize the number of personnel required to assist in performance of a surgical procedure, to minimize the number of personnel who must enter the sterile field, and to minimize the tasks, such as holding a retractor, of personnel during surgical procedures. Further, it is desirable to have available to the surgeon instruments appropriately adapted to each type of procedure.
Coronary Bypass Surgery: The Midsternotomy
Coronary bypass surgery, in which the internal mammary artery is harvested from the chest wall and used for anastomosis of a vessel to bypass poorly functioning coronary arteries, has been performed thousands of times and has become an almost routine procedure for cardiac surgeons. Since the inception and throughout the development of the procedure, coronary bypass surgery has required a midsternotomy to provide access to the heart and coronary arteries. In the midsternotomy, an initial incision is made from the manubrium of the sternum to a point toward the xiphoid. Next, the sternum is split down the middle by means of a reciprocating sternal saw in order to provide access to the coronary arteries and the internal mammary artery. It has been estimated that in 1988, some 350,000 midsternotomy procedures were performed for coronary bypass surgery.
In performing the coronary bypass procedure, following the midsternotomy, it is necessary to retract one side of the split sternum in order to gain access to the thoracic cavity, and particularly to the internal mammary artery. Either the left or right internal mammary artery may be harvested for the bypass, so either side of the chest may need to be retracted. Retractors have been developed in order to provide the requisite retraction of the split sternum. An early example is disclosed in U.S. Pat. No. 4,622,955. The RULTRACT.RTM. internal mammary artery retractor is a more advanced retractor which has been developed to provide left or right internal mammary artery exposure in the undersurface of the chest wall. The RULTRACT.TM. internal mammary retractor has been extensively used in coronary bypass surgery. The RULTRACT.RTM. retractor is not limited to coronary bypass surgery, having been used in various other thoracic surgical procedures, such as lung reduction and pericardial drainage.
The RULTRACT.RTM. internal mammary retractors include a rake plate and two or possibly three rakes. Most frequently, in use the two rakes are applied to one side of the opening formed by a midsternotomy and the rake plate is attached to a lifting device. The lifting device lifts the rake plate and the rakes, applying an upward and outward retraction to the sternum by which the surgical cavity is opened. The sternum is securely held in the open position when the lifting device is locked in position. This exposes the entire course of the mammary artery from its origin to its bifurcation, allowing its dissection. The rakes in the conventional retractor have a relatively small radius of curvature and have quite sharp tips to provide a secure attachment to the sternum. With the sternum securely held in the open position, the coronary artery dissection may then be carried out by the surgeon. In the standard midsternotomy, the retractor provides good exposure and allows the surgeon sufficient access for the dissection of the mammary artery.
After the coronary artery has been harvested, the RULTRACT.RTM. retractor is removed and a sternal retractor is placed in the chest and the grafting and anastomoses is performed. Closure is normally accomplished in this procedure by applying wires or staples to the sternum to hold it together in the properly aligned position for healing.
The midsternotomy is a highly invasive procedure, and much of the difficulty in recovering from a coronary surgical procedure involving a midsternotomy is due to the trauma resulting from the midsternotomy rather than to any trauma inflicted upon the coronary arteries or other thoracic organs and structures. As a result, a need has been identified for a less invasive procedure which will provide the surgeon with access to the coronary and internal mammary arteries with a minimum of trauma to the thoracic region.
The Mid-Cab, A Less Invasive Procedure
A less invasive procedure which has been developed to provide access to the mammary artery and the coronary arteries for coronary bypass surgery is known as the mid-cab or minimally invasive technique. In the mid-cab, an incision is made between the third and fourth rib, in the third intercostal space. The fourth rib is released from the sternum, and the incision is retracted downward by attaching a retractor rake to the fourth rib. A second retractor rake is next attached to the third rib, which is retracted upward and in the cranial direction. With access thus provided to the third rib and in the direction of the upper chest, the surgeon is able to create an opening from the third rib to the first rib or subclavian region. Via this opening, the surgeon is provided with access to the mammary artery, which is progressively dissected from the chest wall as the opening is progressively advanced toward the first rib. With the development of this procedure, a need has been identified for more advanced retractors specially adapted to the mid-cab procedure, and particularly for a retractor which can simultaneously retract the third and fourth ribs in different directions.
It is well known among cardiac surgeons that the position of the internal mammary artery in the chest is variable from patient to patient. For this reason, during the mid-cab procedure, it is sometimes necessary for the surgeon to manipulate the chest wall to provide adequate access to the mammary artery. The surgeon may have to either elevate or depress the chest wall in the region of the first rib in order to gain access to the mammary artery so that it can be dissected in this procedure. Thus, a need has been identified for devices which can assist the surgeon in the less invasive mid-cab procedure, particularly including a retractor capable of two-direction retraction at the site of the intercostal incision and devices for providing elevation and/or depression of the clavicle and first rib region of the chest wall.
Reoperative Coronary Bypass Surgery
As coronary surgery has become increasingly prevalent and postoperative coronary rehabilitation more successful, a larger number of patients are surviving longer than the expected patency of their graft conduits. This has resulted in an increasing number of patients having to undergo a second coronary bypass procedure. The second, or reoperative, procedure has sometimes been referred to as a "re-do" procedure. Unfortunately, the re-do midsternotomy is neither as simple nor as safe as the initial procedure. This is primarily due to the scarring and resultant adhesions which develop between the internal side of the sternum and the underlying organs and tissues of the thoracic cavity following the initial midsternotomy. When the re-do midsternotomy is performed by essentially repeating the steps of the initial procedure, an increase in morbidity and mortality has been observed. Thus, a need has arisen for an alternative procedure.
An alternative procedure which has been adapted to coronary surgery in order to avoid the dangers of the re-do midsternotomy is known as a xiphoid entry. In the xiphoid entry, an initial incision is made along the scar from the previous midsternotomy to a point midway between the xiphoid and the umbilicus. The old sternal wires are removed. The xiphoid process is excised. A single retractor rake is applied to the caudal end of the sternum and the sternum is firmly retracted in an anterior and cranial direction. This allows the surgeon to directly visualize the anterior retrosternal space, so that the retrosternal adhesions can be taken down. The surgeon progressively takes down the adhesions toward the subclavian, until the sternum is freed from the underlying organs. Once this is done, the retractor may be removed and the sternum divided with a reciprocating sternal saw as in the original procedure.
During the retraction particular care must be exercised since, first, the quite sharp rake tips of the standard retractor are applied directly to the lower end of the sternum from which the xiphoid process was excised, and second, a very strong lifting force is required to elevate the entire sternum. The possibility of unintended trauma to the sternum exists. A second problem which has been experienced with the procedure described above is that the entire retractor plate and the extra, non-used rake must be suspended in a central location in the operating field, further obstructing the work area with its already limited space available. A third problem is that due to the rake plate and various parts attaching it to the lifting apparatus, the retraction force applied to the sternum is not transmitted in a simple straight line from the lifting apparatus to the sternum. Thus, a need has been identified for a rake which is more appropriately adapted to the xiphoid entry in a re-do coronary bypass procedure.
In the procedures described in the foregoing and in additional thoracic surgical procedures, the surgeon may be required to adapt the support apparatus for retraction of the patient's body in several directions at once. In such an instance, a single retractor held by a single support device may not be sufficient to provide the retraction required by the surgeon. Furthermore, it may be helpful to the surgeon to combine various embodiments of retraction devices in order to adequately obtain the retraction required.
Accordingly, there is a strong need in the art to provide for surgical retractor apparatus with which to facilitate the development and implementation of new surgical procedures, particularly less invasive procedures such as the mid-cab coronary artery bypass procedure, and for more radical thoracic procedures, such as a lung reduction or other procedure.